Featured Research

Fluorescent light revealed as gauge of coral health: Mysterious glow of light found to correlate with coral stress prior to bleaching

Date:

March 12, 2013

Source:

University of California - San Diego

Summary:

Coral reef decline in recent years due to a variety of threats -- from pollution to climate warming -- has lent urgency to the search for new ways to evaluate their health. A new study has revealed that fluorescence, the dazzling but poorly understood light produced by corals, can be an effective tool for gauging their health.

Share This

Reef-building corals create an oasis of life and diversity in a sparse ocean. Because branching Acropora corals such as those pictured here in the Central Pacific are in peril from climate change, the whole ecosystem is in danger of collapse.

Coral reefs not only provide the world with rich, productive ecosystems and photogenic undersea settings, they also contribute an economic boost valued at hundreds of billions of dollars. But their decline in recent years due to a variety of threats -- from pollution to climate warming -- has lent urgency to the search for new ways to evaluate their health.

Related Articles

A new study by Scripps Institution of Oceanography at UC San Diego scientists has revealed that fluorescence, the dazzling but poorly understood light produced by corals, can be an effective tool for gauging their health.

As described in the March 12 edition of Scientific Reports (a publication of the Nature Publishing Group), marine biologists Melissa Roth and Dimitri Deheyn describe groundbreaking research using fluorescence to test coral stress prompted from cold and heat exposures.

In experimental studies conducted at Scripps, Roth and Deheyn tested the common Indo-Pacific reef-building branching coral Acropora yongei under various temperatures. Branching corals are susceptible to temperature stress and often one of the first to show signs of distress on a reef. Roth and Deheyn found, at the induction of both cold and heat stress, corals rapidly display a decline in fluorescence levels. If the corals are able to adapt to the new conditions, such as to the cold settings in the experiment, then the fluorescence returns to normal levels upon acclimation.

While the corals recovered from cold stress, the heat-treated corals eventually bleached and remained so until the conclusion of the experiment. Coral bleaching, the loss of tiny symbiotic algae that are critical for coral survival, is a primary threat to coral reefs and has been increasing in severity and scale due to climate change. In this study, the very onset of bleaching caused fluorescence to spike to levels that remained high until the end of the experiment. The researchers noted that the initial spike was caused by the loss of "shading" from the symbiotic algae.

"This is the first study to quantify fluorescence before, during, and after stress," said Deheyn. "Through these results we have demonstrated that changes in coral fluorescence can be a good proxy for coral health."

Deheyn said the new method improves upon current technologies for testing coral health, which include conducting molecular analyses in which coral must be collected from their habitat, as opposed to fluorescence that can be tested non-invasively directly in the field.

Corals are known to produce fluorescence through green fluorescent proteins, but little is known about the emitted light's function or purpose. Scientists believe fluorescence could offer protection from damaging sunlight or be used as a biochemical defense generated during times of stress.

"This study is novel because it follows the dynamics of both fluorescent protein levels and coral fluorescence during temperature stress, and shows how coral fluorescence can be utilized as an early indicator of coral stress" said Roth, a Scripps alumna who is now a postdoctoral scientist at Lawrence Berkeley National Laboratory and UC Berkeley.

University of California - San Diego. "Fluorescent light revealed as gauge of coral health: Mysterious glow of light found to correlate with coral stress prior to bleaching." ScienceDaily. ScienceDaily, 12 March 2013. <www.sciencedaily.com/releases/2013/03/130312092918.htm>.

University of California - San Diego. (2013, March 12). Fluorescent light revealed as gauge of coral health: Mysterious glow of light found to correlate with coral stress prior to bleaching. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2013/03/130312092918.htm

University of California - San Diego. "Fluorescent light revealed as gauge of coral health: Mysterious glow of light found to correlate with coral stress prior to bleaching." ScienceDaily. www.sciencedaily.com/releases/2013/03/130312092918.htm (accessed March 3, 2015).

More From ScienceDaily

More Earth & Climate News

Featured Research

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — For almost a century, scientists have been puzzled by a process that is crucial to much of the life in Earth's oceans: Why does calcium carbonate, the tough material of seashells and corals, ... full story

Mar. 3, 2015 — Major cities in the UK are falling behind their international counterparts in terms of their use of smart technologies, according to a new study. The research has found that smart cities in the UK, ... full story

Mar. 3, 2015 — To simulate chimp behavior, scientists created a computer model based on equations normally used to describe the movement of atoms and molecules in a confined space. An interdisciplinary research ... full story

Mar. 3, 2015 — Rather than just waiting patiently for any pollinator that comes their way to start the next generation of seeds, some plants appear to recognize the best suitors and 'turn on' to increase the chance ... full story

Mar. 3, 2015 — Methane emissions are strongly reduced in lakes with anoxic bottom waters. But – contrary to what has previously been assumed – methane removal is not always due to archaea or anaerobic bacteria. ... full story

Mar. 2, 2015 — Hungry, plant-eating insects may limit the ability of forests to take up elevated levels of carbon dioxide in the atmosphere, reducing their capacity to slow human-driven climate change, a new study ... full story

Mar. 2, 2015 — Scientists are reporting advances on how to one day make solar cells stronger, lighter, more flexible and less expensive when compared with the current silicon or germanium technology on the ... full story

Related Stories

Oct. 8, 2014 — Corals are finding refuge within the red mangroves at Hurricane Hole, a mangrove habitat in the US Virgin Islands, from threats such as warming ocean temperatures, solar radiation and increased ocean ... full story

Sep. 5, 2013 — Coral reefs are tremendously important for ocean biodiversity. Unfortunately they have been in great decline in recent years, much of it due to the effects of global climate change. One such effect, ... full story

Jan. 23, 2013 — New research has found a mechanism as to how corals use their pink and purple hues as sunscreen to protect them against harmful sunlight. Many reef corals need light to survive, as they benefit from ... full story

July 12, 2012 — Scientists have discovered two viruses that appear to infect the single-celled microalgae that reside in corals and are important for coral growth and health, and they say the viruses could play a ... full story

Aug. 18, 2010 — Researchers are a step closer to understanding the rapid decline of our coral reefs, thanks to a breakthrough study linking coral immunity with its susceptibility to bleaching and ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.